The general objective of avoiding or minimizing the affect of contaminants on webs from reaching equipment to which the web is being fed is known in a variety of different arts. For example, U.S. Pat. No. 1,418,830 shows the use of flannel wipers for cleaning film being delivered to a motion picture projector.
More pertinent because of the nature of the cleaning device itself is the teaching in U.S. Pat. No. 3,077,625 by Lindau, who uses brushes on opposite sides of strip material such as movie film or magnetic tape. Lindau recognizes that other types of cleaning elements may also be employed, specifically mentioning "fabric, fibers, magnetic and electrostatic elements". In his claims, Lindau addresses the intent "to at least partially dissipate static charges on the moving film".
DiVito U.S. Pat. No. 3,239,868 shows a pair of brushes contacting film from opposite sides, rather than being staggered along the film as in Lindau.
Other types of machines are also provided with various devices for cleaning continuous web material. Examples of such are Lovell U.S. Pat. No. 3,434,273 for scrubbing driving tapes to keep contaminant build-up from affecting the driving speed of endless tapes of a textile strand processing machine, rotary brushes for scrubbing film as shown in U.S. Pat. Nos. 3,470,576 and 3,945,077 and wiping film and then cleaning the wiper web with vacuum rolls.
It is well appreciated that chaff accumulating on continuous computer paper, i.e., edge-perforated, tractor-driven, fan-folded paper is the cause requiring frequent servicing of printers, resulting also in poor print quality and down-time occasioned by the need to manually clean the printer. Such chaff results from paper dust and confetti remaining on the paper supply after the tractor holes and tear perforations are produced in the web. In the case of multi-part forms, the edges are crimped during production. The crimping is staggered along the perforated edges to hold the forms together, and, depending on the type of crimp made, can also result in some crimp lugs breaking loose and becoming additional chaff. Although the problem has been affecting the computer printing industry for a considerable period, and although web cleaning is commonly addressed in other types of web-fed equipment, nothing appears to have been provided to address the problem in this growing product area.